Comparative study of secondary-electron emission from positron and electron bombardment of Ni, Si, and MgO

Abstract

The total secondary-electron yield from positron and electron bombardment with incident energy 20-480 eV on Ni(110), Si(111), and MgO(100) has been measured. The positron-induced and electron-induced secondary-electron yield fit the same "universal" curve but with different scaling parameters. Comparison of the secondary yields suggests that the positron primary beam experiences stronger energy-loss processes than the electron beam in Ni, and qualitatively agrees with calculations and other experiments. The ratio of the maximum electron-induced secondary yield to the positron-induced secondary yield is 0.79, 1.26, and 0.6 for Ni, Si, and MgO, respectively.